From 42643ba35deb8ad1821acfc0577b445ee7ad7548 Mon Sep 17 00:00:00 2001 From: pengdonglin Date: Wed, 16 Sep 2026 21:32:15 +0800 Subject: [PATCH] tracing: Avoid BTF lookup in atomic context The function graph trace formatter can be called from ftrace_dump_one() with interrupts disabled. When ftrace_dump_on_oops is enabled, the trace panic notifier can reach ftrace_dump() from the panic path, including the nmi_panic() path used by the hard lockup detector. btf_find_func_proto() calls bpf_find_btf_id(), which may initialize vmlinux BTF under a mutex. Skip the BTF lookup when running in an atomic context or with interrupts disabled, and fall back to the existing return value formatting. Link: https://patch.msgid.link/20260916133218.1282590-2-dolinux.peng@gmail.com Fixes: ebeed8d4a555 ("tracing/probes: Move finding func-proto API and getting func-param API to trace_btf") Signed-off-by: pengdonglin Signed-off-by: Steven Rostedt --- kernel/trace/trace_btf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace_btf.c b/kernel/trace/trace_btf.c index ee7a04886bf6..b8370ae9bd54 100644 --- a/kernel/trace/trace_btf.c +++ b/kernel/trace/trace_btf.c @@ -15,6 +15,9 @@ const struct btf_type *btf_find_func_proto(const char *func_name, struct btf **b const struct btf_type *t; s32 id; + if (unlikely(in_atomic() || irqs_disabled())) + return NULL; + id = bpf_find_btf_id(func_name, BTF_KIND_FUNC, btf_p); if (id < 0) return NULL;